Examining the effect of heart rate variability biofeedback training on performance and mood states of tennis players

Objective: The aim of this research is to examine the effects of 10 sessions of heart rate variability biofeedback (HRV-BF) training on the mood and serving skills of tennis players. Method: The research was conducted with 24 athletes aged between 10-14 years. Athletes were divided into two groups: experimental and control. Personal resonance frequencies of the experimental group were found before HRV-BF training and 10 sessions of HRV-BF training were applied. No intervention was made to the control group. Pre-test and post-test general self-efficacy and competitive state anxiety questionnaire (CSAI-2C), HRV measurement, and service test were applied to both groups. Results: While no significant difference was observed in the pre-test data of the experimental and control groups, a difference was observed in the post-test data in favor of the experimental group in SDNN, stress index and service test data (p <0.05). When the pre-test and post-test HRV measurements of the experimental group were compared, a significant difference was observed in the parameters SDNN (p = .010, d=0.85), stress (p = .019, d=0.77), and SNS (p = .028, d=0.72). Similarly, while no change was observed in the service test of the control group (p = .574), a significant improvement was observed in the post-test data of the experimental group (p = .013). Conclusion: It has been observed that 10 sessions of HRV-BF training in tennis players improved the athletes' HRV data and serve performance.